Walk-in bathtub with minimal entry threshold

ABSTRACT

A walk-in bathtub is disclosed with a minimal entry threshold height that provides enhanced convenience and safety for physically challenged and/or elderly users. The walk-in bathtub couples directly to a floor drain and does not include water jets or plumbing beneath the tub, thereby allowing the bottom of the tub to rest directly on the floor without being supported by a metal frame. The entry threshold height is less than four inches, preferably less than three inches, and more preferably less than two inches above the floor. The distribution of the tub weight over the floor surface makes it safer to use on weak or compromised floors. The reduced height of the tub allows it to easily pass through conventional doorways, and the reduced weight of the tub allows it to be easily carried and installed.

FIELD OF THE INVENTION

The invention generally relates to bathtubs, and more specifically to walk-in bathtubs.

BACKGROUND OF THE INVENTION

Taking care of personal hygiene needs can be extremely difficult and frustrating for a senior citizen, or for anyone with physical challenges. One of the most difficult and hazardous aspects of personal hygiene for an elderly, infirm, or handicapped person is bathing, since a conventional shower requires a user to stand for an extended period of time, while a conventional bathtub requires a user to step over the side of the bathtub wall, lie down, stand up, and step over the side again. It is not surprising therefore that bathing-related injuries and deaths are quite common for individuals with physical challenges, and that on average at least one person dies each day while using a bathtub or shower.

One approach to making bathing safer and more convenient for the elderly and the physically challenged is a so-called “walk-in bathtub.” A walk-in bathtub is a bathtub with a water-tight door that allows a user to enter and leave the tub without climbing over the side of the tub. Walk-in bathtubs typically also include high walls and a built-in seat that allows a user to bathe or shower while sitting. These features of walk-in bathtubs allow an elderly or physically challenged user to take a bath or shower without climbing over tub walls, standing for an extended period, or lying down and standing up again.

Walk-in bathtubs typically feature water and/or air circulation systems, including pumps and jets, which circulate water and air within the tub, so as to provide additional washing of a physically limited user, therapeutic benefits for the user, and also to enhance the comfort and enjoyment of the user. So as to provide space for air and/or water jets mounted below the floor of the tub, a walk-in bathtub is typically mounted in a frame that suspends the bathtub such that the bottom of the bathtub is at least six inches above the floor, and sometimes as much as nine inches or more above the floor.

However, walk-in bathtubs can be costly to manufacture, and can be difficult to transport and to install due to their height and weight. It is often difficult to bring a walk-in bathtub through a conventional doorway, sometimes making it necessary to temporarily enlarge the size of a doorway or even to cut a temporary hole in a wall so as to bring a walk-in tub into an installation room.

In addition, some desirable installation sites cannot safely accept a walk-in bathtub, because all of the weight of the tub, including the weight of a user occupying the tub and of water filling the tub, is focused onto small areas of the floor beneath the legs of the metal frame. This can be a significant problem for weakly constructed or structurally compromised floors.

Walk-in tubs also tend to drain very slowly. This is because they are usually installed in sites where the drain plumbing was originally designed for use with a conventional bathtub that rested directly on the floor. Drain systems are designed with specific pipe diameters, angles of descent, and trap geometries that cause an optimal mixture of water and air to be drawn down the drain. This mixture of air and water maximizes the rate at which water flows down a drain. However, the drain in the bottom of a walk-in tub is typically elevated as much as nine inches above the underlying floor. When the drain in the bottom of the tub enclosure is connected to the floor drain, this adds as much as nine inches of vertical height to the drain plumbing, causing an improper mixture of air and water to flow down the drain. The result is slow drainage as compared to a conventional bathtub, forcing a user to remain in the walk-in tub for an extended period of time after finishing a bath, since the walk-in tub door cannot be opened until all of the water has drained out of the tub.

Walk-in tubs can also be difficult to install due to irregularities in the installation site. The walls may not be perfectly vertical or perpendicular, there may be pipes or other features protruding from a wall, or the available space may simply be slightly too small for the tub. Although the polymeric materials used in constructing the tub enclosure of a walk-in tub allow for slight adjustments, the metal frame severely limits the degree to which the shape and/or dimensions of the tub can be modified during installation so as to adapt to any custom site requirements.

Finally, and perhaps most importantly, walk-in bathtubs typically include a threshold that is at least six inches above the floor, and sometimes as much as nine inches or more above the floor. Although this configuration provides space for air and/or water jets mounted below the floor of the tub, it poses a significant risk, and a physical and emotional challenge, for the elderly and/or other physically challenged individuals when entering and leaving the tub.

SUMMARY OF THE INVENTION

A walk-in bathtub is claimed which is not suspended above the floor by a frame, and which therefore has a minimal entry threshold height, making it much safer than conventional walk-in bathtubs for use by physically challenged and/or elderly users.

Because the walk-in bathtub of the present invention rests directly on the floor, the weight of the bathtub is distributed over a large area, thereby making it much safer than conventional walk-in bathtubs for use on weak or structurally compromised floors. Supporting the entire bottom of the bathtub on the floor also provides enhanced structural stability, resulting in reduced wear on the tub and a greater feeling of security for the user.

The height of the present invention is also reduced compared to conventional walk-in bathtubs, thereby allowing the present invention to fit more easily through conventional doorways. In addition, because the present invention does not require a metal supporting frame, the cost of the present invention is reduced compared to conventional walk-in bathtubs. The present invention is also lighter than conventional walk-in bathtubs, making it easier and safer to transport and install. Because the present invention does not include a metal frame, the shape and/or dimensions of the tub can be significantly modified during installation so as to adapt to custom site requirements.

Because the present invention rests directly on the floor rather than being supported by a conventional metal frame, the walk-in bathtub drain is at the same height as the drain of a conventional bathtub for which the plumbing at the installation site was designed. This maximizes the rate of water drainage and reduces the waiting time for a user to leave the tub after finishing a bath.

In preferred embodiments of the present invention that include water and/or air circulating jets, all of the jets are located on the sides of the tub. This is in contrast with conventional walk-in bathtubs that require space beneath the tub to accommodate water and/or air jets mounted beneath the tub. Excluding jets on the bottom of the tub also avoids breakage of jets by users stepping on them, and thereby avoids resulting leaks and repairs.

The invention is a walk-in bathtub with minimal entry threshold height. The walk-in bathtub includes a watertight tub enclosure that is able to rest on a floor surface while the watertight tub enclosure is filled with water to a height above the waist of a user sitting on a seat located within the watertight tub enclosure. The walk-in bathtub further includes a doorway in a side of the watertight tub enclosure with a threshold that extends no more than four inches above the floor surface, and a door that forms a watertight seal with the doorway when the door is closed.

In preferred embodiments, the walk-in bathtub further includes a tub drain located in a bottom surface of the watertight tub enclosure, the tub drain being connectable to a corresponding floor drain located in the floor surface directly below the tub drain, so as to allow water contained in the watertight tub enclosure to drain through the tub drain and directly into the floor drain.

In some preferred embodiments, the watertight tub enclosure is able to directly rest on the floor surface without requiring a metal supporting frame. In other preferred embodiments, the walk-in bathtub further includes a water agitation system that is able to direct water into the watertight tub enclosure from at least one side, but not from below. And in some of these embodiments the water agitation system includes a water pump located beneath the seat.

In various preferred embodiments the threshold is not more than three inches above the horizontal floor. And in some embodiments the threshold is not more than two inches above the horizontal floor.

In some preferred embodiments the seat is integral with the watertight tub enclosure, and in other preferred embodiments the seat is removable from the watertight tub enclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a typical walk-in bathtub of the prior art that is supported on a metal frame, includes water and/or air jets mounted underneath, and features a high doorway threshold;

FIG. 2A is a perspective view of a preferred embodiment of the present invention with the door open, showing the minimal height of the doorway threshold, a seat and a tub drain;

FIG. 2B is a perspective view of the embodiment of FIG. 2A with the door closed, showing a user sitting on the seat and water filling the bathtub up to the user's chest;

FIG. 2C is a side view of an embodiment similar to the embodiment of FIG 2A, but more compact and more vertical, shown with the outer shell removed;

FIG. 2D is a top view of the embodiment of FIG. 2C;

FIG. 3 is a cutaway view of the embodiment of FIG. 2A, showing a water and/or air pump located under the seat, water and/or air jets positioned along the sides of the tub, and a tub drain in the bottom of the tub configured for connection to a corresponding floor drain; and

FIG. 4 is a close-up, cut away view of the embodiment of FIG. 2A, showing the tub drain aligned with and connected to a corresponding floor drain.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

FIG. 1 shows a perspective view of a typical prior art walk-in bathtub 100. The walk-in bathtub 100 includes a high-walled tub enclosure 102 with a seat 104 at one end that allows a user to sit while taking a bath or a shower. A doorway 106 with a water-tight door 108 allows a user to enter and leave the tub enclosure 104. A pump 110 located under the seat 104 pumps water and/or air through hoses 112 to jets located on the sides and beneath the tub enclosure 102 so as to agitate the water in the tub enclosure 102. The tub enclosure 102 is supported by a metal frame 114 with legs that 116 that rest on the floor 118. Because the entire weight of the walk-in bathtub 100 rests on the legs 116, including the weight of a user while in the tub and of water contained therein, this prior art approach poses a danger to weakly constructed or compromised floors.

The metal frame 114 supports the tub enclosure 102 above the floor 118 so as to provide space under the tub enclosure 102 for water jets and for a drain hose (not shown). Because of the added height created by the metal frame 114, the threshold 120 of the doorway is raised above the floor 118 by at least six inches, and sometimes by as much as nine inches or more, which can pose a serious hazard to physically challenged and/or elderly users. The added height of the tub 100 due to the frame 114 also makes it more difficult for the walk-in tub 100 to pass through a conventional doorway, sometimes requiring a doorway to be temporarily enlarged or a temporary hole to be cut in a wall so as to bring the tub 100 into the installation room. Also, the weight of the metal frame 114 makes the walk-in tub 100 difficult to carry and install, risking injury to individuals performing the installation.

FIG. 2A is a perspective view of a walk-in bathtub 200 in a preferred embodiment of the present invention. As in the prior art 100, the preferred embodiment of FIG. 2A includes a seat 206 on which a user (220 in FIG. 2B discussed below) can be seated, a water agitation system (302 in FIG. 3 discussed below) that can direct water 222 and/or air into the watertight tub enclosure 202, a doorway 218 with an entry and exit threshold 216 and a door 224 that forms a watertight seal with the doorway 218 when the door 224 is closed. Unlike the prior art 100, however, the water agitation system does not include jets in the bottom of the watertight tub enclosure 202.

Also, the tub drain 214 located at the bottom 210 of the watertight tub enclosure 202 in the embodiment of FIG. 2A is configured for direct connection to a corresponding drain in the floor 204. As a result, the watertight tub enclosure 202 of the present invention does not require a metal frame, and instead rests directly on the floor 204, allowing the threshold 216 of the doorway 218 to be not more than five inches above the floor 204.

In preferred embodiments, the entry and exit threshold 216 is preferably less than three inches above the horizontal floor 204, and more preferably less than two inches above the horizontal floor 204 or even substantially flush with the floor 204. The reduced threshold height of the present invention significantly improves its safety for physically challenged and/or elderly users. Distribution of the weight over a large area of the floor significantly increases the safety for weakly constructed and/or compromised floors, and improves the structural durability and stability of the tub. The reduced overall height and weight of the present invention also make it easier to carry and install, and allow it to pass more easily through a conventional doorway.

FIG. 2B is a perspective view of the preferred embodiment 200 of FIG. 2A. A user 220 is seated on the seat 206 of the watertight tub enclosure 202, and the watertight tub enclosure 202 is filled with water 222 to a height above the waist of the user 220. The water agitation system 302 is directing water 222 and/or air into the watertight tub enclosure 202 from the sides 208 of the walk-in bathtub 200.

FIG. 2C is a side view of a preferred embodiment similar to the embodiment of FIG. 2A, but with a more compact and vertical configuration. The outer shell has been removed, and the motor 226 that drives the agitation system can be seen below the seat. For clarity of illustration, the hoses and wires associated with the motor 226 have been omitted from FIG. 2C. FIG. 2D is a top view of the embodiment of FIG. 2C without water or occupant. In this embodiment, the seat 206 has a curved back for the comfort of a user 220, and both the seat and floor are covered with a non-slip surface (indicated in the figure by cross-hatching). The water jets have been omitted from FIG. 2D for clarity of illustration.

FIG. 3 is a cutaway view of the preferred embodiment 200 of FIG. 2A, showing the water agitation system 302. The water agitation system 302 includes an air pump 226 mounted beneath the seat 206 and air jets 212 along at least one side 208 of the watertight tub enclosure 202. Similar embodiments include a water pump and water jets. Jets 212 are not included beneath the tub enclosure 202 so that the tub enclosure 202 does not need to be elevated and supported above the floor 204, for example by using a metal frame 114 as is shown in the prior art example of FIG. 1.

FIG. 4 is an enlarged cutaway view of the preferred embodiment 200 of FIG. 2A, showing the tub drain 214 aligned directly above and coupled with a corresponding floor water drain 402. The floor water drain 402 allows water 222 contained in the watertight tub enclosure 202 to drain through the tub drain 214 and into the floor water drain 402 without a need for hoses or other plumbing to connect the tub drain 214 to a remote floor drain. Because the tub drain 214 is located at the same height as a conventional bathtub drain, and is not raised above the floor, the tub drain 214 works together with the existing drainage system to provide the proper mixture of air and water in the drainage flow, thereby maximizing the drainage rate.

Other modifications and implementations will occur to those skilled in the art without departing from the spirit and the scope of the invention as claimed. Accordingly, the above description is not intended to limit the invention except as indicated in the following claims. 

1. A walk-in bathtub with minimal entry threshold height, the walk-in bathtub comprising: a watertight tub enclosure that is able to rest on a floor surface while the watertight tub enclosure is filled with water to a height above the waist of a user sitting on a seat located within the watertight tub enclosure; a doorway in a side of the watertight tub enclosure with a threshold that extends no more than four inches above the floor surface; and a door that forms a watertight seal with the doorway when the door is closed.
 2. The walk-in bathtub of claim 1, further including a tub drain located in a bottom surface of the watertight tub enclosure, the tub drain being connectable to a corresponding floor drain located in the floor surface directly below the tub drain, so as to allow water contained in the watertight tub enclosure to drain through the tub drain and directly into the floor drain.
 3. The walk-in bathtub of claim 1, wherein the watertight tub enclosure is able to directly rest on the floor surface without requiring a metal supporting frame.
 4. The walk-in bathtub of claim 1, further comprising a water agitation system that is able to direct water into the watertight tub enclosure from at least one side, but not from below.
 5. The walk-in bathtub of claim 4, wherein the water agitation system includes a water pump located beneath the seat.
 6. The walk-in bathtub of claim 1, wherein the threshold is not more than three inches above the horizontal floor.
 7. The walk-in bathtub of claim 1, wherein the threshold is not more than two inches above the horizontal floor.
 8. The walk-in bathtub of claim 1, wherein the seat is integral with the watertight tub enclosure.
 9. The walk-in bathtub of claim 1, wherein the seat is removable from the watertight tub enclosure. 